Disruption of both the AP endonucleases impairs the growth of <i>M.tuberculosis</i> in THP-1 macrophages.

<p>THP-1 cells were infected with wild-type <i>M.tuberculosis</i>, MtbΔ<i>end</i>, MtbΔ<i>xthA</i> or MtbΔ<i>end</i>Δ<i>xthA</i> at an MOI of 1∶5 (bacteria∶macrophage). The number of intracellular viable bacteria was determined on each alternative day for 6 days. A significant attenuation in the growth of MtbΔ<i>end</i>Δ<i>xthA</i> in comparison to wild-type <i>M.tuberculosis</i> was observed on the 4^th and 6^th day of infection. The growth of single mutants MtbΔ<i>end</i> and MtbΔ<i>xthA</i> was comparable with wild-type <i>M.tuberculosis</i>. The values are represented as the mean (±SE) of three independent infections and the experiment was repeated three times. ***, <i>P</i><0.001 (Two way ANOVA).